Dioscorea Batatas Decne Research Articles

Role of Reductive Soil Disinfestation and Chemical Soil Fumigation on the Fusarium Wilt of Dioscorea batatas Decne Suppression

Reductive soil disinfestation (RSD) and chemical soil fumigation (CSF) comprise the most popular pre-planting soil management strategies. Their efficiency in suppressing several plant diseases in agricultural production systems has been compared. However, the disease-control effect of these methods on Fusarium wilt disease in Dioscorea batatas Decne (D. batatas) remains unclear. Importantly, dissimilarities in the impact of their bio-predictors on plant health have not been well characterized. Herein, four treatments, including no treatment (CK), RSD with gran chaff (GC-RSD) and molasses (MO-RSD), and CSF with dazomet (DA-CSF), were performed in a pot experiment using D. batatas-diseased soil. Compared with the CK treatment, the Fusarium oxysporum population significantly decreased by 88.89–97.78% following the DA-CSF, GC-RSD, and MO-RSD treatments. The bacterial community and functional composition of the soil were considerably altered by these treatments. However, the incidence of Fusarium wilt disease in D. batatas was significantly decreased in the two RSD-treated soils, rather than in DA-CSF-treated soils. Bacterial α-diversity and population as well as some key nitrogen-related functional gene expressions as bio-predictors were significantly lower in DA-CSF-treated soil than in RSD-treated soil. In particular, the core (e.g., Azotobacter, Phenylobacterium, Clostridium, Bradyrhizobium, Microvirga, and Caulobacter) and unique (e.g., Pseudomonas, Brevundimonas, Flavobacterium, Ochrobactrum, and Sphingobacterium) functional microbiomes in RSD-treated soil exerted a positive impact on soil functional composition of the soil and plant growth. Taken together, our results indicate that RSD outperformed CSF in promoting plant health by regulating the bacterial community and functional composition.

Anti-neuroinflammatory activity of 6,7-dihydroxy-2,4-dimethoxy phenanthrene isolated from Dioscorea batatas Decne partly through suppressing the p38 MAPK/NF-κB pathway in BV2 microglial cells

Ethnopharmacological relevanceThe rhizome of Dioscorea batatas Decne (called Chinses yam) widely distributed in East Asian countries including China, Japan, Korea and Taiwan has long been used in oriental folk medicine owing to its tonic, antitussive, expectorant and anti-ulcerative effects. It has been reported to have anti-inflammatory, antioxidative, cholesterol-lowering, anticholinesterase, growth hormone-releasing, antifungal and immune cell-stimulating activities. Aim of the studyNeuroinflammation caused by activated microglia contributes to neuronal dysfunction and neurodegeneration. In the present study, the anti-neuroinflammatory activity of 6,7-dihydroxy-2,4-dimethoxy phenanthrene (DHDMP), a phenanthrene compound isolated from Dioscorea batatas Decne, was examined in microglial and neuronal cells. Materials and methodsA natural phenanthrene compound, DHDMP, was isolated from the peel of Dioscorea batatas Decne. The anti-neuroinflammatory capability of the compound was examined using the co-culture system of BV2 murine microglial and HT22 murine neuronal cell lines. The expression levels of inflammatory mediators and cytoprotective proteins in the cells were quantified by enzyme-linked immunosorbent assay and Western blot analysis. ResultsDHDMP at the concentrations of ≤1 μg/mL did not exhibit a cytotoxic effect for BV2 and HT22 cells. Rather DHDMP effectively restored the growth rate of HT22 cells, which was reduced by co-culture with lipopolysaccharide (LPS)-treated BV2 cells. DHDMP significantly decreased the production of proinflammatory mediators, such as nitric oxide, tumor necrosis factor-α, interleukin-6, inducible nitric oxide synthase, and cyclooxygenase-2 in BV2 cells. Moreover, DHDMP strongly inhibited the nuclear translocation of nuclear factor κB (NF-κB) and phosphorylation of p38 mitogen-activated protein kinase (MAPK) in BV2 cells. The compound did not affect the levels and phosphorylation of ERK and JNK. Concurrently, DHDMP increased the expression of heme oxygenase-1 (HO-1), an inducible cytoprotective enzyme, in HT22 cells. ConclusionsOur findings indicate that DHDMP effectively dampened LPS-mediated inflammatory responses in BV2 microglial cells by suppressing transcriptional activity of NF-κB and its downstream mediators and contributed to HT22 neuronal cell survival. This study provides insight into the therapeutic potential of DHDMP for inflammation-related neurological diseases.

Phytoglycoprotein isolated from Dioscorea batatas Decne promotes intestinal epithelial wound healing.

Dioscorea batatas Decne (DBD) has been used to heal various illnesses of the kidney and intestine as an herbal medicine in Asia. As a source of therapeutic agents, many glycoproteins have been isolated from mushrooms and plants, but the functional role of glycoprotein in intestinal epithelial wound healing has not been understood yet. In the present study, we investigated the wound healing potentials of the 30 kDa glycoprotein (DBD glycoprotein) isolated from DBD in human intestinal epithelial (INT-407) cells. We found that DBD glycoprotein (100 μg·mL-1) significantly increased the motility of INT-407 cells for 24 h by activating protein kinase C (PKC). DBD glycoprotein stimulated the activation of p38 mitogen-activated protein kinase (MAPK), which is responsible for the phosphorylation of NF-κB inhibitor α (IκBα). DBD glycoprotein increased the level of profilin-1 (PFN1), α-actinin and F-actin expression via activation of transcription factor, nuclear factor-kappa B (NF-κB) during its promotion of cell migration. Experimental mouse colitis was induced by adding dextran sulfate sodium (DSS) to the drinking water at a concentration of 4% (W/V) for 7 days. We figured out that administration of DBD glycoprotein (10 and 20 mg·kg-1) lowers the levels of disease activity index and histological inflammation in DSS-treated ICR mice. In this regard, we suggest that DBD glycoprotein has ability to promote the F-actin-related migration signaling events via activation of PKC and NF-κB in intestinal epithelial cells and prevent inflammatory bowel disease.

6,7‐dihydroxy‐2,4‐dimethoxy phenanthrene isolated from Dioscorea batatas peel suppresses microglia‐associated neuroinflammation in vitro

Inflammation occured in the neural tissue is a cause of neurodegenerative diseases. Our previous study showed that the ethanolic extract of Dioscorea batatas Decne peel promoted antioxidant mechanism in colonic epithelial cells and attenuated inflammatory response in activated macrophages. Recently, 6, 7‐dihydroxy 2, 4‐dimethoxy phenanthrene (DDP) has been identified as one of the bioactive compounds having antioxidative and anti‐inflammatory activities. The current study aimed at examining the neuroprotective potential of DDP by staving off neuroinflammation. Our data demonstrated that (1) DDP decreased glutamate‐induced murine hippocampal neuronal cell death; hlowever, there was no significant increase in ARE‐luciferase activity, (2) DDP decreased the expressions of nuclear NF‐κB and its downstream proteins in BV2 murine microglial cells and thereby lowered NO production and cytokine secretion, and (3) DDP increased the production of antioxidant enzyme, heme oxygenase 1(HO‐1) in BV2 murine microglial cell. These results indicate that DDP suppressed microglial activation which generally causes neuroinflammation. In consideration of our observations implying that DDP may not directly stimulate the antioxidant mechanism in neuronal cells for its in vitro neuroprotective effect, DDP would possibly enhance neuronal cell survival due to its anti‐neuroinflammatory capability in microglia. The interaction between neuronal cells and microglia cells in culture as well as under physiological conditions awaits further study.

Inhibitory Functions of Novel Compounds from Dioscorea batatas Decne Peel on HMGB1-mediated Septic Responses

Inhibition of high mobility group box 1 (HMGB1) signaling and restoration of endothelial integrity are emerging as promising therapeutic strategies for managing severe vascular inflammatory diseases. Dioscorea batatas Decne (DBD, Chinese yam), a perennial plant which belongs to Dioscoreaceae, is widely cultivated across Korea, Japan, China, and other tropical and subtropical regions, and both the aerial parts and roots of this plant are used for food and medicinal purposes. Here, we determined the effects of the two phenanthrene compounds from DBD peel, 2,7-dihydroxy-4,6-dimethoxyphenanthrene (1) and 6,7-dihydroxy-2,4-dimethoxyphenanthrene (2), on HMGB1-mediated septic responses and survival rate in cecal ligation and puncture (CLP)-induced septic model. The anti-inflammatory activities of compounds 1 and 2 were monitored by lipopolysaccharide (LPS)- or CLP-induced release of HMGB1. The anti-septic activities of compounds 1 and 2 were determined by measuring permeability, leukocyte adhesion and migration, and pro-inflammatory protein activation in HMGB1-activated human umbilical vein endothelial cells (HUVECs) and mice. Compounds 1 and 2 inhibited HMGB1 release and downregulated HMGB1-mediated inflammatory responses in HUVECs. Compounds 1 and 2 also inhibited HMGB1-induced hyperpermeability and leukocyte migration in mice. Additionally, treatment with compounds 1 and 2 reduced CLP-induced HMGB1 release and sepsis-related mortality and pulmonary damage in vivo. Our results indicate that the compounds 1 and 2 are potential therapeutic agents for treating severe vascular inflammatory diseases via HMGB1 signaling pathway inhibition.

Quantitative Analysis of Bioactive Phenanthrenes in Dioscorea batatas Decne Peel, a Discarded Biomass from Postharvest Processing.

Dioscorea batatas Decne (Chinese yam) has been widely cultivated in East Asia for the purposes of food and medicinal uses for centuries. Along with its high nutritional value, the medicinal value of D. batatas has been extensively investigated in association with phytochemicals such as allantoin, flavonoids, saponins and phenanthrenes. Phenanthrenes are especially considered the standard marker chemicals of the Chinese yam for their potent bioactivity and availability of analysis with conventional high performance liquid chromatography with ultraviolet detection (HPLC-UV) methods. In order to investigate how much the contents of phenanthrenes are in the actual food products provided for consumers, D. batatas tuber was peeled and separated into its peel and flesh as in the conventional processing method. A quantitative analysis using the HPLC-UV method revealed that phenanthrenes are concentrically present in the D. batatas peel, while phenanthrenes are present in the flesh under the limit of detection. The difference in the contents of phenanthrenes is estimated to have arisen the considerable difference of antioxidant potential between the peel and the flesh. The results from this study suggest the high value of the discarded biomass of the Chinese yam peel and the necessity for the utilization of the Chinese yam peel.

Inhibitory effects of compounds isolated from Dioscorea batatas Decne peel on particulate matter-induced pulmonary injury in mice

ABSTRACTParticulate matter 2.5 (PM2.5), with an aerodynamic diameter of ≤2.5 μm, is the primary air pollutant that plays a key role associated with lung injury produced by loss of vascular barrier integrity. Dioscorea batatas Decne (Chinese yam), a perennial plant belonging to Dioscoreaceae family, is widely cultivated in tropical and subtropical regions across Asia. Both aerial parts and root of D. batatas are consumed for nutritional and medicinal purposes. The aim of this study was to (1) identify the bioactive compounds present in D. batatas peel which may be responsible for inhibition of PM2.5-induced pulmonary inflammation in mice and (2) examine in vitro mechanisms underlying the observed effects of these compounds on mouse lung microvascular endothelial cells. The measured parameters include permeability, leukocyte migration, proinflammatory protein activation, reactive oxygen species (ROS) generation, and histology. Two phenanthrene compounds, 2,7-dihydroxy-4,6-dimethoxyphenanthrene (1) and 6,7-dihydroxy-2,4-dimethoxyphenanthrene (2) were isolated from D. batatas peels. Both these phenanthrene compounds exhibited significant scavenging activity against PM2.5-induced ROS and inhibited ROS-induced activation of p38 mitogen-activated protein kinase. In addition, enhancement of Akt pathway, involved in the maintenance of endothelial integrity, was noted. These phenanthrene compounds also reduced vascular protein leakage, leukocyte infiltration, and proinflammatory cytokine release in the bronchoalveolar lavage fluid obtained from PM2.5-induced lung tissues. Evidence thus indicates that phenanthrene compounds derived from D. batatas may exhibit protective effects against PM2.5-induced inflammatory lung injury and vascular hyperpermeability in mice.

Anti-inflammatory and antioxidant effects of 2, 7-dihydroxy-4, 6-dimethoxy phenanthrene isolated from Dioscorea batatas Decne

Our previous study showed that the ethanol extract of Dioscorea batatas Decne (Chinese yam) peel upregulated certain antioxidant enzymes and had the anti-inflammatory activity. In this study, 2, 7-dihydroxy-4, 6-dimethoxy phenanthrene (DDP) was isolated from yam peel extract as a potent antioxidative enzyme inducer through bioassay-guided fractionation using HepG2-ARE cells, and subjected to examination for its anti-inflammatory activity as well as antioxidant activity. DDP decreased the levels of inflammatory mediators in LPS-stimulated Raw 264.7 macrophage and reduced the level of reactive oxygen species in tert-butyl hydroperoxide-challenged Raw 264.7 cells. Moreover, DDP enhanced the expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and its downstream heme oxygenase-1 proteins while it decreased the expression of iNOS, COX-2, proinflammatory cytokines via nuclear factor-κB pathway. However, the combinatorial treatment with DDP and the inhibitor of Nrf2 or HO-1 activity did not affect the levels of inflammatory biomarkers, suggesting that anti-inflammatory action by DDP is achieved by the mechanism independent of Nrf2 signaling pathway. In conclusion, DDP was found to be a strong antioxidant and anti-inflammatory agent and warrants further in vivo efficacy study for future use as a functional food ingredient.

Protective Effect of Dioscorea batatas Peel Extract Against Intestinal Inflammation

Abstract Dioscorea batatas Decne (Chinese yam), a perennial trailing plant, has been used as a traditional medicine due to its beneficial biological effects. Recent studies reported that yam bark p...

Protective Effects of Dioscorea batatas Flesh and Peel Extracts against Ethanol-Induced Gastric Ulcer in Mice.

Gastric ulcer is a major digestive disorder and provoked by multifactorial etiologies, including excessive alcohol consumption. In this study, we examined the gastroprotective effect of aqueous and ethanolic extracts of Dioscorea batatas Decne (DBD; commonly called Chinese yam) flesh or peel against acidified ethanol-induced acute gastric damage in mice. Our findings demonstrated that oral supplementation of aqueous or ethanolic extracts of DBD flesh or peel before ulcer induction was significantly effective in macroscopically and histologically alleviating ethanol-induced pathological lesions in gastric mucosa, decreasing the plasma levels of inflammatory mediators, such as nitric oxide and interleukin-6, attenuating the gastric expression of cyclooxygenase-2, and increasing the gastric content of prostaglandin E2. In particular, pretreatment with the flesh extract prepared in 60% ethanol prominently decreased the expression of biomarkers of oxidative stress, including the plasma levels of 8-hydroxy-2-guanosine and malondialdehyde, and restored heme oxygenase-1 expression and superoxide dismutase activity in the stomach. Overall, these findings suggest that the oral supplementation with DBD extract, especially flesh ethanol extract, prior to excessive alcohol consumption, may exert a protective effect against ethanol-induced gastric mucosal damage in vivo, presumably through the activation of the antioxidant system and suppression of the inflammatory response.

Hepatic anti-inflammatory effect of hexane extracts of Dioscorea batatas Decne: Possible suppression of toll-like receptor 4-mediated signaling

The hepatic anti-inflammatory potential of hexane extracts of Dioscorea batatas Decne edible part (EDH-1e) and bark (EDH-2b) were investigated in Western-type diet-fed apolipoprotein E null [ApoE (-/-)] mice and HepG2 cells. EDH-1e and EDH-2b suppressed the increased levels of tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, transforming growth factor beta 1 (TGF-β1), vascular cell adhesion protein 1 (VCAM-1), and monocyte chemoattractant protein-1 (MCP-1), and reduced infiltration of monocytes into liver tissue. The protein levels of Toll-like receptor 4 (TLR4) were also downregulated by EDH-1e and EDH-2b treatment as were the levels of activator protein 1 (AP-1), c-fos, and c-jun in the livers from Western-type diet-fed ApoE (-/-) mice and in lipopolysaccharide-stimulated HepG2 cells. Taken together, EDH-1e and EDH-2b attenuated hepatic inflammation and fibrosis via suppression of the TLR4-AP1-mediated signaling pathway.

Quality Characteristics of Yackwa made with Yam (Dioscorea batatas Decne) Powder

Quality Characteristics of Yackwa made with Yam (Dioscorea batatas Decne) Powder

Quality Characteristics of Yackwa made with Yam (Dioscorea batatas Decne) Powder

Quality Characteristics of Yackwa made with Yam (Dioscorea batatas Decne) Powder

Antioxidant and Anti-inflammatory Effects of Yam (Dioscorea batatas Decne.) on Azoxymethane-induced Colonic Aberrant Crypt Foci in F344 Rats.

Yam (Dioscorea batatas Decne.) has long been used as a health food and oriental folk medicine because of its nutritional fortification, tonic, anti-diarrheal, anti-inflammatory, antitussive, and expectorant effects. Reactive oxygen species (ROS), which are known to be implicated in a range of diseases, may be important progenitors of carcinogenesis. The aim of this study was to investigate the modulatory effect of yam on antioxidant status and inflammatory conditions during azoxymethane (AOM)-induced colon carcinogenesis in male F344 rats. We measured the formation of aberrant crypt foci (ACF), hemolysate antioxidant enzyme activities, colonic mucosal antioxidant enzyme gene expression, and colonic mucosal inflammatory mediator gene expression. The feeding of yam prior to carcinogenesis significantly inhibited AOM-induced colonic ACF formation. In yam-administered rats, erythrocyte levels of glutathione, glutathione peroxidase (GPx), and catalase were increased and colonic mucosal gene expression of Cu/Zn-superoxide dismutase (SOD), Mn-SOD, and GPx were up-regulated compared to the AOM group. Colonic mucosal gene expression of inflammatory mediators (i.e., nuclear factor kappaB, inducible nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor alpha, and interleukin-1beta) was suppressed by the yam-supplemented diet. These results suggest that yam could be very useful for the prevention of colon cancer, as they enhance the antioxidant defense system and modulate inflammatory mediators.

안동지역 약용작물의 표고별 지표성분 분석

*Department of Medicinal Crops, Andong Agrotechnology Center, Pungsan 997-1, Korea.**Department of Food Science and Biotechnology, Andong University, Andong 760-749, Korea.ABSTRACT : The contents of index components in 5 medicinal crops cultivated at different heights in Andong area. Thecontents of allantoin in Dioscorea batatas Decne and catalpol in Rehmannia glutinosa Liboschitz were not differentby cultivation heights (100 ~ 200 m). But the contents of index components in Astragalus membranaceus and Angelica acutilobaKitagawa were higher in samples cultivated at elevated heights. At 700 m of heights, the contents of formononetin andastragaloside I in Astragalus membranaceus were 1.20 and 201.2㎍/g, respectively. The contents of decursin and nodakeninin Angelica acutiloba Kitagawa were 68.3 and 4.20 ㎎/g, respectively. Thus Astragalus membranaceus and Angelica acutilobaKitagawa are recommended to be cultivated in higher altitude. Key Words : Medicinal Crops, Height, Liquid Chromatography-Mass Spectrometry

Dioscorin Pre-treatment Protects A549 Human Airway Epithelial Cells from Hydrogen Peroxide-Induced Oxidative Stress

Hydrogen peroxide (H(2)O(2)) is a highly reactive oxygen species involved in lung and bronchial epithelium injury. Increased H(2)O(2) levels have been reported in expired breath condensates of patients with inflammatory airway diseases such as chronic obstructive pulmonary disease. Protecting airway epithelial cells from oxidative stress is an important task in the prevention and management of airway diseases. Previous studies demonstrate that yam (Dioscorea batatas Decne) has antioxidant and anti-trypsin activities. This study evaluated the validity of dioscorin in vitro. The results showed that dioscorin attenuated the alteration of H(2)O(2) on G2/M cell cycle arrest. This might be associated with the activation of IκB and subsequent inactivation of NF-κB. Furthermore, dioscorin suppressed IL-8 secretion and reduced changes of adhesion molecule expressions in H(2)O(2)-injured A549 cells. These results help in understanding the potential of traditional Chinese herbal medicine as treatment for airway inflammatory diseases.

Diarylheptanoids from aerial bulbils of Dioscorea batatas

Dioscorea batatas Decne. (Dioscoreaceae) grows as a perennial herb, and is widely distributed or cultivated in Korea, Japan and China. The rhizomes and bulbils of D. batatas have been used as tonics, and crude drug for the treatment of diabetes and diarrhea in the traditional Chinese medicine. Also, its rhizome is a well-known edible plant. Previous studies on D. batatas have afforded mainly steroids, steroid glycosides and phenanthrene derivatives. In our continuing studies to find bioactive compound from natural products, we have found that the MeOH extract of D. batatas bulbil has anti-inflammatory activity. The MeOH extract was fractionated by using Diaion HP-20 column with consecutive elution (H2O˜MeOH, and acetone). A new and five known diarylheptanoids were isolated from the subfractions by means of chromatographic separation. The known compounds were identified as meso-hannokinol, hexahydrocurcuminol, 5-hydroxyplatyphyllone, (3R,5S)-3,5-dihydroxy-1-(4′-hydroxyphenyl)-7-(3″-methoxy-4″-hydroxyphenyl)heptane, (3R,5S)-3,5-dihydroxy -1-(4′-hydroxyphenyl)-7-(3″,4″-hydroxyphenyl) heptane, respectively by comparison of their spectral data with literature values. The structure of a new diarylheptanoid was determined as (1S, 3R, 5S)-1,3,5-trihydroxy-1,7-bis(4′-hydroxyphenyl)heptane from its spectral data and chemical evidence. Inhibitory effects of the isolated compounds on nitric oxide, TNF-α and IL-6 production were evaluated in lipopolysaccharide-activated RAW 264.7 cells.

Suppression of adhesion molecule expression by phenanthrene-containing extract of bulbils of Chinese Yam in vascular smooth muscle cells through inhibition of MAPK, Akt and NF-κB

Atherosclerosis is a chronic inflammatory disease associated with increased expression of adhesion molecules in vascular smooth muscle cells (VSMCs). The objective of this study was to examine the in vitro effects of extract from aerial Bulbil of Dioscorea batatas Decne (Db-Ex) on the ability to suppress the expression of adhesion molecules induced by TNF-α. We also identified bioactive components from a methanol extract. VSMCs pre-exposed to Db-Ex (10–100μg/ml) were stimulated with TNF-α (10ng/ml). Preincubation of VSMCs for 2h with Db-Ex dose-dependently inhibited TNF-α-induced adhesion of THP-1 monocytic cells and mRNA and protein expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). Db-Ex treatment decreased ROS production and the amount of phosphorylated form of p38, ERK, JNK and Akt in TNF-α-stimulated cells, suggesting that Db-Ex inhibits adhesion molecule expression possibly through MAPK and Akt regulation. Db-Ex also suppressed TNF-α-activation NK-κB. This effect was mediated through degradation of IκBα and nuclear translocation of the p65 subunit of NF-κB. These results suggest that Db-Ex inhibits monocyte adhesion and the TNF-α-mediated induction of adhesion molecules in VSMC by downregulating the MAPK/Akt/NF-κB signaling pathway, which may explain the ability of Db-Ex to suppress inflammation within the atherosclerotic lesion.

Ethanol extracts of yam potently reduce atherosclerosis in ApoE‐deficient mice

Atherosclerosis is a chronic inflammatory disease initiated by vascular inflammation and monocyte recruitment. Yams belong to the plant family Dioscoreae and have been known to have a variety of nutritional benefits with high levels of vitamins, dietary fibers, and minerals. However, the effect of yam extracts on inflammatory diseases is not known yet. Herein we evaluate whether extracts from edible part (H1) or bark region (H2) of yam (Dioscorea batatas Decne) have a protective effect against atherosclerosis in experimental mice. 51 male ApoE −/− mice and 17 control (C57BL/6J) mice were fed a high‐fat/high‐cholesterol diet for 21 weeks. To examine the effect of dietary yam extracts on atherosclerosis, 17 of the ApoE −/− mice were given H1 and another 17 of the ApoE −/− mice were given H2 (oral administration of 200 mg/kg body weight, 3 times per week). Both H1 and H2 showed suppressive effects on the lipid deposition and the local infiltration of monocytes/macrophages in aorta. In addition, administration of H1 and H2 decreased serum levels of CRP, MCP‐1 and total cholesterol, while it slightly increased the level of HDL. Moreover, they attenuated the level of oxLDL in serum. The present study demonstrates that yam extracts, H1 and H2, might have a protective effect against atherosclerosis by regulating proinflammatory mediators in serum as well as preventing atherosclerotic lesion development.

Anti-inflammatory activity of bark of Dioscorea batatas DECNE through the inhibition of iNOS and COX-2 expressions in RAW264.7 cells via NF-κB and ERK1/2 inactivation

We identified a bioactive herbal medicine with anti-inflammatory activity from an ethanol extract derived from the bark of Dioscorea batatas DECNE (BDB) in RAW264.7 cells. We examined the effects of BDB on nitric oxide (NO) and prostaglandin E 2 (PGE 2) production in LPS-induced RAW264.7 cells. BDB consistently inhibited both NO and PGE 2 production in a dose-dependent manner, with an IC 50 of 87–71 μg/ml, respectively. The reduction of NO and PGE 2 production were accompanied by a reduction in iNOS and COX-2 protein expression, as evaluated by Western blotting. To evaluate the action mode of BDB and its ability to inhibit iNOS and COX-2 protein expression, we assessed the effects of BDB on nuclear factor-κB (NF-κB) DNA-binding activity, NF-κB-dependent reporter gene activity, inhibitory factor-κB (IκB) phosphorylation and degradation, and p65 nuclear translocation. BDB suppressed DNA-binding activity and reporter gene activity as well as translocation of the NF-κB p65 subunit. BDB also down-regulated IκB kinase (IKK), thus inhibiting LPS-induced both phosphorylation and the degradation of IκBα. In addition, BDB also inhibited the LPS-induced activation of ERK1/2.